The present invention generally relates to a method for treating prostheses having an apertured structure. In particular, this invention relates to a method and a device for saturating a prosthesis with a liquid.
The term xe2x80x9capertured structurexe2x80x9d refers to those prostheses (such as, for example, so-called vascular grafts or the suture rings of cardiac valve prostheses) comprising, entirely or in part, from tissue structures, spongy masses and/or having elaborate geometries with slits, cavities and spaces, i.e., apertures. In use, such prostheses tend to hold air inside them with a consequent risk of the formation of blood clots in the period following implantation, due to the presence of air bubbles contained or otherwise held by the prosthesis. The simple solution, sometimes adopted during the implantation operation, of immersing the prosthesis in, for example, a physiological saline bath, does not satisfactorily solve the problem, both because the results can depend, possibly significantly, on the time dedicated to this treatment and the ability of the person conducting it, and because it is in any case difficult to remove all the air from the prosthesis.
The present invention therefore aims to eliminate in a radical manner the risk of the occurrence of these negative phenomena. The invention also concerns devices which can be used in the performance of this method. An important advantage of the invention is that the liquid such as, for example, physiological saline that is introduced into the pores, even the deep pores, to replace the air that is naturally present, can be supplemented with drugs such as, for example, antibiotics, anti-thrombotic drugs, drugs that promote the integration between the prosthesis and the surrounding biological tissues, or growth factors. Because the liquid is held in the pores, the drug or drugs can exert their action locally and extended over time. It is noted that the word xe2x80x9cdrugxe2x80x9d, as used herein, also includes the possible use of a binding agent applied to the prosthesis in order to attract thereto, with a binder-ligand association mechanism, pharmacologically active agents introduced into the patient""s body.
In one aspect, this invention is a method for the treatment of a prosthesis having an apertured structure, comprising placing a prosthesis having an apertured structure into a holding chamber; producing sub-atmospheric pressure in the holding chamber; and introducing a liquid into the holding chamber to saturate the prosthesis. The sub-atmospheric pressure is selected so that after the introduction of the liquid into the holding chamber, the prosthesis is substantially free of air. The liquid may be substantially inert, e.g., physiological saline, or may comprise a drug. Sub-atmospheric pressure is established by connecting the holding chamber to a vacuum line, and liquid is introduced into the holding chamber by connecting the holding chamber to a liquid supply line, the liquid supply line being provided with a cut-off element. The sub-atmospheric pressure of the holding chamber reaches approximately xe2x88x92850 mbar. Preferably, the holding chamber is connected to the vacuum line for less than about 60 seconds and the liquid flows into the chamber for less than about 60 seconds.
In a second aspect, this invention is a device for the treatment of a prosthesis having an apertured structure comprising a casing defining a holding chamber for a prosthesis, the casing including an opening for the introduction of the prosthesis into the chamber and a sealing element disposed around the opening to allow a sub-atmospheric pressure to be drawn within the casing; a first fluid line leading to the casing for connecting the chamber to a source of sub-atmospheric pressure; a second fluid line for connecting the chamber to a source of liquid; and a valve acting on the first and second fluid lines to connect the chamber in succession with the source of sub-atmospheric pressure and the source of liquid. The source of liquid preferably is a container and a vacuum pump provides a source of sub-atmospheric pressure. Preferably, a safety cut-off element is interposed in the second fluid line, selectively activatable to open or close the second fluid line. Also, in a preferred embodiment, a filtration element comprising a sterile, fluid-permeable barrier is interposed in the first fluid line. A casing carrying a connector defines a common part of the first and second fluid lines. The connector may be a luer connector. The casing may have two complementary parts connectable together with the interposition of a sealing element; the two complementary parts may be sealingly connected together by locking means.
In a third aspect, this invention is a kit for the treatment of a prosthesis having an apertured structure, comprising a casing defining a holding chamber for a prosthesis, the casing including an opening for the introduction of the prosthesis into the chamber and a sealing element disposed around the opening to permit sub-atmospheric pressure to be drawn within the casing; a first fluid line leading to the casing for connecting the chamber to a source of sub-atmospheric pressure; a second fluid line for connecting the chamber to a source of liquid; and a valve acting on the first and second fluid lines to connect the chamber in succession with the source of sub-atmospheric pressure and the source of liquid, wherein the casing, the first fluid line, the second fluid line, and the valve are packaged in a sterile envelope.
In a fourth aspect, this invention is a container for a prosthesis having an apertured structure used to saturate the prosthesis with a liquid, the container comprising a casing defining a holding chamber for the prosthesis; at least one connector associated with the casing and configured to enable the connection of the prosthesis holding chamber to a source of sub-atmospheric pressure, the casing being sealably closable and having a structure that retains the substantial integrity of the prosthesis in the presence of sub-atmospheric pressure within the prosthesis holding chamber, and a liquid reservoir connected to the prosthesis holding chamber, such that the liquid from the reservoir saturates the apertured structure of the prosthesis as a result of the liquid being drawn into the holding chamber due to the sub-atmospheric pressure. The connector may be either a luer connector or a perforable membrane. Alternatively, the connector may be a luer connector integral with a perforable membrane.